News Feeds

An 11-page document that’s attributed to a Pentagon whistleblower has provided new cases in the controversy over unidentified anomalous phenomena — also known as UAPs, unidentified flying objects or UFOs.

The document, released today in conjunction with a House subcommittee hearing on UAPs, lays out details about what’s said to be a special access program called Immaculate Constellation. It accuses officials in the federal government’s executive branch of a “criminal conspiracy” that has been managing issues surrounding UAPs and evidence for non-human intelligence “without congressional knowledge, oversight or authorization for some time, quite possibly decades.”

Over the past few years, the Department of Defense has become more open to discussing UAP reports publicly, while insisting that there have been no substantiated reports of alien visitations. During today’s hearing, lawmakers called on the Pentagon to be more transparent in its investigations.

“It is clear, from my experience and what I’ve seen, that there is something out there,” said Rep. Andy Ogles, R-Tenn. “The question is, is it ours? Is it someone else’s? Or is it otherworldly? … We must know, and anyone who prevents us from gaining access to that information, I would consider that criminality, because we have U.S. personnel who may very well be in harm’s way.”

The document claims that the Immaculate Constellation program has imagery and other data relating to encounters with a variety of anomalous objects. “From 1991 to 2022, the most common UAP shapes reported in this [U.S. government] dataset were spheres/orbs, discs/saucers, ovals/tic-tacs, triangles, boomerang/arrowhead, and irregular/organic,” it said. The irregular objects were described as having a “floating brain” or “jellyfish” appearance.

Michael Shellenberger, an author and journalist who received the document from the purported whistleblower, said he verified the source’s credentials and assured lawmakers that the document was authentic. He also said he’s continuing to gather reports from other sources.

“Since my reporting on this Immaculate Constellation last month, another source came forward,” Shellenberger said. “He told me that they saw a roughly 13-minute-long, high-definition, full-color video of a white orb UAP coming out of the ocean approximately 20 miles off the coast of Kuwait. It was filmed from a helicopter. Then halfway through the video, the person said, the orb is joined by another orb that briefly comes into the frame from the left before rapidly moving again out of the frame.”

Shellenberger said there may be “hundreds, maybe thousands” of UAP reports in the Immaculate Constellation database.

Mick West, a retired software engineer who specializes in analyzing UAP reports, was generally skeptical of the claims made during the hearing, which was conducted jointly by two subcommittees under the aegis of the House Oversight Committee. Nevertheless, West was intrigued by the purported whistleblower report — and said the Pentagon’s All-Domain Anomaly Resolution Office, or AARO, should follow up.

“The UFO document discussed in congressional testimony today contains descriptions of some interesting-sounding videos,” West said in a posting to the X social-media platform. “If these exist, I urge @DoD_AARO to make as many of these videos public as possible and share their analysis so we can get some clarity ASAP.”

In addition to Shellenberger, the witnesses at today’s hearing included retired Navy Rear Adm. Tim Gallaudet, who served as the acting administrator of the National Oceanic and Atmospheric Administration during the Trump administration; Luis Elizondo, a former intelligence official who is now an advocate for UAP disclosure; and Mike Gold, a former NASA associate administrator who was a member of NASA’s independent UAP study panel and is now chief growth officer at Redwire.

Witnesses at the UAP hearing included, from left, Tim Gallaudet, Luis Elizondo, Michael Shellenberger and Mike Gold. (Credit: House Oversight Committee via YouTube)

In advance of the hearing, Gallaudet came in for some strong criticism from Sean Kirkpatrick, who was in charge of AARO in 2022-2023 and is now chief technology officer for defense and intelligence programs at Oak Ridge National Laboratory in Tennessee. “Mr. Gallaudet is clearly still bitter that I didn’t hire him into AARO when he came looking for a job,” Kirkpatrick said in a statement distributed on X. “His predisposed tendencies for conspiracies without evidence made him unsuitable for a job that required objectivity and evidence-based reason.”

Kirkpatrick and others involved in the UAP debate have suggested that the likeliest explanations for anomalous aerial sighting have to do with advanced technologies that are being secretly employed by rival nations, including Russia and China. But questions about potential alien intrusions, secret crash retrievals and exotic technologies repeatedly came up during the hearing.

In response to such questions, Gallaudet said he believed some of the reports about UAPs could be attributed to non-human higher intelligence. Elizondo agreed. “Although much of my government work on the UAP subject still remains classified, excessive secrecy has led to grave misdeeds against loyal civil servants, military personnel and the public — all to hide the fact that we are not alone in the cosmos,” Elizondo said.

In contrast, Gold declined to weigh in definitively on questions about extraterrestrials. “I just don’t know,” he said. “I think we must be modest in our assumptions that we’re looking for intelligence that could be biological. It might not.”

For example, Gold said, some UAPs may be controlled by artificial intelligence. “We assume that all intelligence would be like us, and every time we look out in the universe, we are humbled relative to what we don’t know, in terms of the forms of intelligence and what it may take,” he said. “l probably can’t answer your question, but I think the ultimate answer is going to surprise us all.”

The witnesses and the lawmakers seemed unanimous in their support for greater transparency about UAP sightings. Congress is currently considering legislation that would strengthen current requirements for UAP disclosure and whistleblower protection.

Rep. Jared Moskowitz, D-Fla., hinted that more information may be forthcoming when Donald Trump returns to the White House. “This has been bipartisan, bicameral,” Moskowitz said. “As we get into a new administration, the president-elect has talked about opportunities to declassify information on UAPs, and I hope he lives up to that promise.”

The post Congressional Hearing Fuels Fresh Debate About UFOs appeared first on Universe Today.

One of the most challenging aspects of astrobiology and the Search for Extraterrestrial Intelligence (SETI) is anticipating what life and extraterrestrial civilizations will look like. Invariably, we have only one example of a planet that supports life (Earth) and one example of a technologically advanced civilization (humanity) upon which to base our theories. As for more advanced civilizations, which statistically seems more likely, scientists are limited to projections of our own development. However, these same projections offer constraints on what SETI researchers should search for and provide hints about our future development.

In a series of papers led by the Blue Marble Space Institute of Science (BMSIS), a team of researchers examines what Earth’s level of technological development (aka. “technosphere”) will look like in the future. In the most recent installment, they offer a reinterpretation of the Kardashev Scale, which suggests that civilizations expand to harness greater levels of energy (planet, host star, and galaxy). Instead, they suggest that the Kardashev Scale establishes upper limits on the amount of stellar energy a civilization can harness (a “luminosity limit”) and that civilizations might circumvent this by harnessing stellar mass directly.

As with the previous study in this series, the research was led by Jacob Haqq-Misra, the Senior Research Investigator at the Blue Marble Space Institute of Science. He was joined by George Profitiliotis, an Affiliate Research Scientist at the BMSIS and a Research Member of the Working Group on SETI and Law at the International Institute of Space Law (IISL), and Clement Vidalb, a researcher with the Center Leo Apostel (CLEO) at the Free University of Brussels. The paper “Projections of Earth’s Technosphere: Luminosity and Mass as Limits to Growth” is being reviewed for publication in Acta Astronautica.

Energy consumption estimated in three types of civilizations defined by the Kardashev Scale. Credit: Wikimedia Commons

The Kardashev Scale, named after Soviet-Russian astrophysicist and radio astronomer Nikolai Kardashev (1932 – 2019), was first proposed in his seminal paper, “Transmission of Information by Extraterrestrial Civilizations,” released in 1964. In it, Kardashev suggested what types of radio frequencies (and at what energies) scientists should search for to discern possible transmissions of an extraterrestrial civilization (ETC). In keeping with the idea that there may be civilizations billions of years older than humanity, he reasoned that these civilizations could harness levels of energy beyond human capabilities.

To characterize the level of an ETC’s development, Kardashev proposed a three-level scale based on the amount of energy they could harness. This included:

• Type I – Planetary Civilizations: ETCs that have developed the means to harness and store all of their home planet’s energy, an estimated 4×1019 erg/sec.
• Type II – Stellar Civilizations: ETCs that have evolved to the point where they can harvest all the energy emitted by their star – 4×10³³ erg/sec.
• Type III – Galactic Civilizations: ETCs able to harness the energy of an entire galaxy – 4×1044 erg/sec.

However, this scale reflected the assumption that civilizations and their energy needs will grow exponentially. This is in keeping with observations of humanity’s own “technosphere,” which refers to the human-made infrastructure, machinery, communications, and other indications of technological activity (aka “technosignatures”). Basically, it reflects our limited perspective when it comes to the kinds of behaviors advanced ETCs would exhibit. As Haqq-Misra told Universe Today via email:

“Earth is our only known example of a planet with technology, so the search for extraterrestrial civilizations must begin by thinking about how to search for analogs to Earth’s technosignatures today and possible technosignatures that could arise in Earth’s future. We should also try to stretch our minds to consider other, non-terrestrial, and more exotic possibilities, but even such imaginative possibilities will always either begin with (or contrast with) what we know is possible based on existing or known physics on Earth.”

Artist’s impression of a Dyson Sphere, a proposed alien megastructure that is the target of SETI surveys. Finding one of these qualifies in a “first contact” scenario. Credit: Breakthrough Listen/Danielle Futselaar

Traditional applications of the Kardashev Scale predict that growth will be exponential and have even considered how this could give rise to a civilization capable of utilizing the energy output of all stars in the Universe – a Type IV Cosmic Civilization! This application has motivated many searches for civilizations that have reached these scales of vast energy utilization, as indicated by megastructures (e.g., Dyson Spheres, Clarke Bands, etc.) and other advanced technospheres. For their study, Haqq-Misra and his colleagues took a different approach:

“Our study re-examines these assumptions by noting that civilizations can follow different trajectories for their expansion in space and their energy consumption. This involves tradeoffs between ‘exploration’ and ‘exploitation,’ and there are many possibilities for how a civilization might develop along these two dimensions. Some civilizations may prioritize exploration in physical distance without ever needing to expand their energy consumption to Kardashev Type I or Type II scales. Other civilizations may focus on exploitation and increase their energy use more locally. Some civilizations may attempt to find an optimal balance between exploration and exploitation.

“We also point out that the Kardashev scale is better considered as a theoretical limit to a civilization that utilizes stellar energy (luminosity). Rather than describing a trajectory that advanced civilizations will follow, the Kardashev scale is the uppermost limit for a civilization’s energy use, as it relates to expansion in physical distance, but a limit that may never actually be achieved due to thermodynamic efficiency limits. In other words, the Kardashev scale describes an upper-limit to the tradeoffs between exploration and exploitation, and a civilization that is dependent on stellar luminosity for its energy needs will always fall below the energetic and spatial limits described by the Kardashev scale.”

The scenario Haqq-Misra and his colleagues proposed presents some new and interesting possibilities for advanced civilizations. For example, suppose humanity ever reaches the limit of how much energy it can harness from our Sun. In that case, it may not choose to explore and settle other star systems (with the intent of harnessing the energy of more planets and more stars). Instead, they may turn to harvesting stellar mass itself.

Illustration of a white dwarf accreting mass by stripping its non-degenerate companion. Credit: ESO/Kornmesser

“Civilizations like this that consume stars, which we call ‘stellivores,’ would be able to expand in energy use beyond the luminosity limits of the Kardashev scale,” said Haqq-Misra. “We are not at this level as a civilization on Earth yet, but we can at least think about the possibility that harvesting mass and converting it into energy (as Einstein’s famous equation describes) provides a way for a civilization to reach energy use scales beyond those envisioned by the Kardashev scale.”

Like all projections on humanity’s future development, this study also has implications for future SETI surveys. This is in keeping with the assumption that ETCs in our galaxy would be older and more advanced than humanity at this point. It’s also consistent with the principle that “if we can conceive of it, someone else has probably done it already.” As Haqq-Misra explained, future SETI surveys should examine “accreting binaries,” closely orbiting binary stars with mass flowing from one star to another.

Maqq-Misra and his colleagues recommend that scientists observe accreting binaries to search for abnormal behavior, which could indicate technological activity:

“If some civilizations actually do evolve into stellivores, then some of these may look like such accreting binary star systems. We cannot claim that all, or even most, accreting binaries are actually technological civilizations, but we also cannot rule out the possibility that some of them could in fact be technological. It is worth keeping our minds open and actually searching for such evidence of advanced and exotic civilizations rather than ruling them out before we look.”

Further Reading: arXiv

The post New Study Examines How Extraterrestrial Civilizations Could Become “Stellarvores.” appeared first on Universe Today.

The mega-coral measures 34 metres by 32 metres – making it larger than a blue whale – and it is thought to be three centuries old

Navigating the harsh terrain of other rocky worlds has consistently been challenging. The Free Spirit campaign unfortunately failed in its goal to will the plucky Martian rover out of the morass it found itself in, despite two years of continual effort from some of the world’s best engineers. To combat this difficulty, other engineers have turned to alternative propulsion methods, and a team of researchers in the EU have done just that for their work on an autonomous mining robot. They decided to use an Archimedes screw as their primary propulsion method.

The team has already successfully tested various prototype iterations of their miniaturized mining robot. More recently have released a paper that detailed a mobility platform based on four individually controlled Archimedes screws that could be useful for more than just mining underground.

As with most engineering projects, they started with a computer model, which resulted in a CAD model that the team tested on different terrain. They weren’t the first ones to think of using an Archimedes screw as a driving mechanism. Existing research has pointed out that it is not the most efficient on some terrains. However, it can navigate almost all terrains to at least some degree.

The work described in the paper was part of the ROBOMINERS project, supported by the EU.
Credit – ROBOMINERS YouTube Channel

Kinematics models are critical to the development of any robot, and one with a relatively obscure propulsion system is no exception. Since Archimedes screws can be modeled from any observational angle, coordinating the operation of each of the four independent screws to align correctly to the desired direction required some complex modeling that was eventually hosted as part of the control algorithm on board a computer seated on top of the mobile platform.

Another part of the control algorithm required the robot to understand how it was orientated, and to do that, the team developed an integrated network of sensors. These ranged from time of flight positioning systems, which allowed the robot to gauge the distance to an object, to force sensors on the screws themselves that would ensure they wouldn’t over-torque and burn out their drive motors.

Once the sensors were selected and the preliminary control code was written, it was time to put it to a real environmental test. The team built a physical prototype, partly out of 3D-printed parts, and set about moving it about on various surfaces. The drive system worked well on snow, sand, frozen ground, and mud. However, it was mainly used to traverse level surfaces rather than the more complicated slopes that it might encounter in some environments, such as Mars. 

Fraser discusses how we might use robots to explore the Moon.

That is not to say the system cannot adapt to slopes – just that there is more work to be done. ROBOMINERS, the EU project focused on building an autonomous mining robot, is looking to complete its final prototype soon, and the results of the drive platform testing shown in this latest paper will help contribute to that. Someday, it might contribute to a similar robot on the moon or Mars.

Learn More:
Gkliva et al – A Multi-Terrain Robot Prototype With Archimedean Screw Actuators: Design, Realization, Modeling, and Control
UT – NASA Tests a Robotic Snake That Could Explore Other Worlds
UT – Snake Rovers Might be the Best Way to Explore the Surface and Tunnels on Mars
UT – NASA Redoubling Efforts to Contact Spirit

Lead Image:
Prototype of the screw-driven robot on leafy ground.
Credit – Gkliva et al.

The post A Screw-Driven Robot Could Autonomously Mine Rocky Worlds appeared first on Universe Today.

Mars has been a fascination to us for centuries. Early observations falsely gave impressions of an intelligent civilisation but early visiting probes revealed a stark, desolate world. Underneath the surface is a few metres of water ice and a recent study by NASA suggests sunlight could reach the layer. If it does, it may allow photosynthesis in the meltwater. On Earth this actually happened and biologists have found similar pools teeming with life. 

The exploration of Mars by space probes began in the 1960’s. It began with the Soviet Union Mars 1 and NASA’s Mariner mission and was soon followed by the well known Viking landers in 1976. They were the first missions to test surface material for signs of life. The Mars Pathfinder mission took along the Sojourner rover and was followed by Spirit and Opportunity rovers after the turn of the century. Curiosity rover was among the latest of the visitors along with Perseverance and China’s Tianwen-1. The focus of later missions has been the hunt for water and analysis of the climate and geology of the planet. This was not only to understand the conditions as the planet evolved but to pave the way for human exploration. 

The Viking 1 lander was the first to capture a real selfie. This is a mosaic of high-resolution images of Viking 1 at Chryse Planitia. Image Credit: NASA/JPL.

To date, there has been no evidence of life on Mars. The question has intrigued us for decades though. Of all the planets in the Solar System, Mars is the most likely place to have once harboured primitive life, chiefly due to the discovery of liquid water in the distant past. Evidence of ancient dried river beds has been found across the planet with mineral deposits indicating that Mars was once warmer, wetter and potentially far more habitable. Even organic molecules have been discovered by the Curiosity and Perseverance rovers but researchers continue to hunt for evidence (past or present) of microbial life. 

Mars, Credit NASA

A team of researchers from NASA have published a paper articulating their use of computer modelling to help the search. They have shown that sunlight can shine through the Martian water ice, perhaps even enough for photosynthesis to occur in shallow pools of meltwater. 

There are two types of ice on Mars, frozen water and frozen carbon dioxide. The study explored water ice which had mostly formed as snow had fallen on the surface during a Martian ice age millions of years ago. The team believe that the key to the study are the dust particles that obscure light reaching the deeper layers of ice. They suggest that sunlight will warm the dark dust more than surrounding ice and then cause ice to warm and melt. Some scientists believe that ice at the surface cannot melt due to the thin dry atmosphere causing it to turn straight to a gas. This won’t apply to the ice deeper in the surface layer. 

Almost pure water ice is seen in the ejecta surrounding this impact crater (8 meters in diameter), which formed in 2008. The only reason we can see ice at the surface here is because this crater is so young. As time passes, the ice will all sublimate and no longer be present at the surface. Image Credit: High Resolution Imaging Science Experiment camera, NASA/JPL-Caltech/University of Arizona.

Such a process has been observed on Earth where dust heats ice, melts and allows the dust to sink. Over time, the dust particles will stop sinking through the ice but still generate enough heat to melt the ice and create tiny voids. It is here that thriving ecosystems have been found hosting simple forms of life. 

The paper published in Nature Communications Earth & Environment, suggests the dusty ice can produce enough light at depths up to 3 metres to allow photosynthesis to occur. The subsurface pools of meltwater are protected from evaporating by the ice above. It also provides some protection from radiation too providing a possibly habitable environment for simple forms of life. The authors suggest the areas would likely form in the Martian tropics between 30 and 60 degrees latitude in both hemispheres. 

Source : Could Life Exist Below Mars Ice? NASA Study Proposes Possibilities

The post How Life Could Live Under the Ice on Mars appeared first on Universe Today.

An asteroid struck Mars 11 million years ago and sent pieces of the red planet hurtling through space. One of these chunks of Mars eventually crashed into the Earth and is one of the few meteorites that can be traced directly to Mars. This meteorite was rediscovered in a drawer at Purdue University in 1931 and therefore named the Lafayette Meteorite. During early investigations of the Lafayette Meteorite, scientists discovered that it had interacted with liquid water while on Mars. Scientists have long wondered when that interaction with liquid water took place. Scientists have recently determined the age of the minerals in the Lafayette Meteorite that formed when there was liquid water.

NASA’s Jet Propulsion Lab has announced a second round of layoffs for 2024, this time laying off 325 people – about 5% of its workforce. The announcement was made on Nov. 12 in a memo sent to employees, which notes the layoffs could have been even larger. The last cut was made this past February, when 530 employees were let go. Part of the issues which forced the layoffs comes from the the possible cancelation of the Mars Sample Return mission. With the October 2024 launch of Europa Clipper, JPL doesn’t have a flagship mission in the pipeline right now.

As with the layoffs in February, the cuts have nothing to do with the individual performance; it’s all budget-related and an attempt to balance the books. NASA Headquarters passed on funding constraints in the current budget to JPL, and while JPL has tried to manage them, the results are the two rounds of difficult layoffs.  

“This is a message I had hoped not to have to write,” JPL Director Laurie Leshin said in the memo sent to all staff members. “Despite this being incredibly difficult for our community, this number [of layoffs] is lower than projected a few months ago thanks in part to the hard work of so many people across JPL.”

Dr. Laurie Leshin has been the director of the Jet Propulsion Laboratory since May 2022. Credit: JPL.

Leshin said the lab’s leadership has had to deal with “continued funding challenges” and an uncertain future as NASA has been juggling and reconsidering its priorities for deep space exploration. She noted that the reduction was spread across nearly all areas of JPL, including technical, project, business, and support areas to meet the available funding for Fiscal Year 2025. Leshin said that the outcome of the presidential election last week did not have any bearing on the layoffs.

“We have taken seriously the need to re-size our workforce, whether direct-funded (project) or funded on overhead (burden). With lower budgets and based on the forecasted work ahead, we had to tighten our belts across the board, and you will see that reflected in the layoff impacts,” Leshin wrote.

All employees were told to work from home today (Nov. 13) and everyone would receive an email whether their position was being eliminated or not. Leshin said JPL would offer “personalized support to our laid-off colleagues who are part of the workforce reduction, including offering dedicated time to discuss their benefits, and several other forms of assistance.”

Artist’s concept of a Europa Clipper mission. Credit: NASA/JPL

This second round of layoffs were not a surprise. During a recent town hall with employees, Leshin discussed the continued funding challenges and projections of what the potential impact on the JPL workforce could look like. She indicated her team had been working through multiple workforce scenarios to address the changes in funding, with the goal of minimizing adverse effects on JPL’s capabilities and workers. But despite their efforts, the conclusion was that this additional workforce reduction was inevitable.

After the layoffs today, JPL will be left with about 5,500 regular employees.

“These are painful but necessary adjustments that will enable us to adhere to our budget while continuing our important work for NASA and our nation,” JPL said in a statement.

On social media, JPL employees called the news “devastating,” and “awful.” Another said, “Can’t imagine the stress this will produce.”

But Leshin also said she believed this would be the last workforce reduction needed for the foreseeable future and that staffing levels at this point are now “stable and supportable.”

“While we can never be 100 percent certain of the future budget, we will be well positioned for the work ahead,” Leshin wrote. “This may not help much in this difficult moment, but I do want to be crystal clear with my thoughts and perspective. If we hold strong together, we will come through this, just as we have done during other turbulent times in JPL’s nearly 90-year history.”

Dare Mighty Things The “Dare Mighty Things” sign at JPL. Image by Nancy Atkinson.

JPL has a long and storied history — “Dare Mighty Things” is the Lab’s motto — with the Lab’s origins dating back to the 1930s, when Caltech professor Theodore von Kármán oversaw pioneering work in rocket propulsion. In the 1960s, JPL began to develop robotic spacecraft to explore other worlds, beginning with the Ranger and Surveyor missions to the Moon, quickly followed by Mariner missions to Mercury, Venus and Mars. Now, missions and instruments built or managed by JPL have visited every planet in our Solar System as well as studying the Sun. The iconic Voyager missions have now entered interstellar space.

Despite the difficult layoffs, Leshin was hopeful for what’s to come for JPL.

“We are an incredibly strong organization—our dazzling history, current achievements, and relentless commitment to exploration and discovery position us well for the future,” she wrote.

The post NASA’s JPL Lays Off Another 325 People appeared first on Universe Today.

Will we ever understand how life got started on Earth? We’ve learned much about Earth’s long, multi-billion-year history, but a detailed understanding of how the planet’s atmospheric chemistry evolved still eludes us. At one time, Earth was atmospherically hostile, and its transition from that state to a planet teeming with life followed a complex path.

What made Earth so special? Research shows that while Earth is completely different from its neighbouring planets now, in the past, it shared many atmospheric characteristics with modern-day Venus and Mars. How did Earth turn out so different?

A better understanding of Earth’s atmospheric journey can help us understand some of the distant exoplanets we’ve detected. In the near future, new telescopes will be revealing more details of exoplanet atmospheres. Many puzzles await, and some of the solutions to understanding them could be found on ancient Earth.

Ancient Earth had a reducing atmosphere, which means that there was a lack of free oxygen. The atmosphere contained reducing gases like hydrogen and methane. These gases quickly react with oxygen and remove it from the atmosphere. Some of those same molecules also react with UV light, and the chemical reactions produce organic molecules.

While that’s a general outline of some aspects of ancient Earth’s atmosphere, there’s a lot of detail that needs to be constrained before a clearer picture emerges of Earth’s transformation.

Researchers at Tohoku University, the University of Tokyo, and Hokkaido University have developed a new model of atmospheric chemical reactions that sheds light on how Earth’s atmosphere evolved and how the first life may have arisen.

The research is “Self-Shielding Enhanced Organics Synthesis in an Early Reduced Earth’s Atmosphere.” It’s published in the journal Astrobiology, and Tatsuya Yoshida from Tohoku University is the lead author.

Before life could appear, Earth needed a good supply of important prebiotic molecules like formaldehyde (H2CO) and poisonous hydrogen cyanide (HCN). These molecules are critical because they can undergo a wide variety of reactions to produce the more complex molecules life requires. They produce amino acids, sugars, and nucleobases, which are the building blocks for DNA and RNA.

Research shows that a highly reduced atmosphere like ancient Earth’s is a candidate for producing these important prebiotic molecules, especially if it’s above a primordial ocean. Earth’s primordial ocean, or proto-ocean, was also much different from the modern ocean. Among other things, it was acidic because of volcanic gases. It was also hot.

Ancient Earth had hot, acidic oceans and a reducing atmosphere that lacked free oxygen. Image Credit: NASA/T.Pyle

“Ancient Earth was nothing like our current home,” explains co-author Shungo Koyama, also from Tohoku University. “It was a much more hostile place; rich in metallic iron with an atmosphere containing hydrogen and methane.”

The Sun’s UV radiation bombarded ancient Earth unimpeded by an ozone layer, driving chemical reactions in the ancient Earth’s atmosphere, oceans, and crust.

That much is understood. But what scientists desire is a better understanding of all of the details. “However, the branching ratio between organic matter formation and oxidation remains unknown despite its significance on the abiotic chemical evolution of early Earth,” the authors explain.

The researchers developed a photochemical model for a reduced Earth’s atmosphere primarily containing H2 and CH4. Their model is based on one that’s been successfully applied to Jupiter’s atmosphere, the atmospheres of ancient and modern Mars, and runaway greenhouse atmospheres. The model considers 342 separate chemical reactions and also includes atmospheric hydrogen escape and atmospheric mixing.

The young Sun emitted more intense UV radiation than the modern Sun. The UV broke water molecules down into hydrogen and oxygen radicals. Radicals have one unpaired electron, which makes them chemically reactive. Much of the hydrogen escaped to space, while the oxygen did not.

Illustration of what the Sun may have been like 4 billion years ago. Scientists think that overall, the young Sun was fainter than it is now. But it was also more active and had a higher level of magnetic activity. That activity made the Sun emit more UV than it does now. Credit: NASA’s Goddard Space Flight Center/Conceptual Image Lab

The oxygen radicals combined with methane led to the creation of organic molecules like HCN and H2CO.

Hydrocarbons, such as acetylene (C2H2) and methylacetylene (C3H4), were also present in the atmosphere. These chemicals absorbed some UV, shielding the lower atmosphere from photodissociation. “According to our results, UV absorptions by gaseous hydrocarbons such as C2H2 and C3H4 significantly suppress the H2O photolysis and following CH4 oxidation,” the authors explain. The atmospheric methane helped drive the production of organics.

That allowed organic molecules to accumulate into a prebiotic soup, which could’ve provided the building blocks for life.

“Accordingly, nearly half of initial CH4 possibly becomes converted to heavier organics along with deposition of prebiotically essential molecules such as HCN and H2CO on the surface of a primordial ocean for a geological timescale order of 10-100 Myr,” the authors write.

This diagram shows the evolution of Earth’s ancient atmosphere estimated by this study. Earth initially had a reducing atmosphere with lots of H2 and some CH4. Intense UV energy from the Sun split water into hydrogen and oxygen radicals, with much of the hydrogen escaping into space. CH4 that remains in the atmosphere is converted into organics. Earth loses its ancient CH4 and H2-rich atmosphere, the CH4 decomposes, and a layer of organics several hundred meters thick accumulates. Image Credit: Yoshida et al. 2024

As time went on and the reduced atmosphere evolved, H2CO and HCN were continuously synthesized and accumulated in the ocean. H2CO and HCN are considered to be critical in prebiotic chemistry. According to these results, Earth’s early atmosphere was a major source of these important prebiotic molecules. They didn’t need to come from meteorites or comets.

The authors calculate that a layer of organic several hundred meters thick may have covered the ocean. “The continuous supply of these prebiotically important molecules could potentially lead to the synthesis of amino acids, nucleobases, sugars, and their polymers,” the researchers write.

“There may have been an accumulation of organics that created what was like an enriched soup of important building blocks. That could have been the source from which living things first emerged on Earth,” said lead author Yoshida.

The model shows that Earth’s early atmosphere was eerily similar to modern-day Mars and Venus. However, Earth evolved into a completely different world. How?

This research doesn’t explain it all. But it does deepen our understanding of the evolutionary track Earth followed.

The question becomes, is Earth unique? Or is it a common path that exoplanets in other Solar Systems can follow?

The post Lessons From Ancient Earth’s Atmosphere: From Hostile to Hospitable appeared first on Universe Today.

Air pollution has been linked to eczema before, and now a study of more than 280,000 people has strengthened the association

Dozens of perforated pebbles from an archaeological site in Israel may be early examples of spindle whorls, a rotating tool used in textile making that was a step towards inventing the wheel

Food production is responsible for more than a third of greenhouse gas emissions. To get everyone the food they need in a warming world, governments worldwide must invest in securing our food systems

Scientists using observations from NASA's Neil Gehrels Swift Observatory have discovered, for the first time, the signal from a pair of monster black holes disrupting a cloud of gas in the center of a galaxy.

Few questions have captivated humankind more than the origin of life on Earth. How did the first living cells come to exist? How did these early protocells develop the structural membranes necessary for cells to thrive and assemble into complex organisms? New research has uncovered a plausible explanation involving the reaction between two simple molecules.

Engineers have invented a protective coating for concrete pipes that could help drastically reduce the formation of fatbergs in sewers.

Astronomers have identified three ultra-massive galaxies -- nearly as massive as the Milky Way -- already in place within the first billion years after the Big Bang. This surprising discovery was made possible by the James Webb Space Telescope's FRESCO program, which uses the NIRCam/grism spectrograph to measure accurate distances and stellar masses of galaxies. The results indicate that the formation of stars in the early Universe was far more efficient than previously thought, challenging existing galaxy formation models.

Rates of near-sightedness are rising all over the world. But solutions to the epidemic are coming into focus and could be simpler than you think

Selection for bigger tomatoes has made the fruits less sweet, but now it has been shown that gene editing can make them sweeter without decreasing yields

Researchers mapped Earth’s ionosphere, part of the upper atmosphere, using signal data from 40 million phones – a method that could improve GPS accuracy and help track space weather

Palaeontologists have pieced together the brain structure of a bird that lived 80 million years ago named Navaornis hestiae, thanks to a remarkably well-preserved fossil  

There is a region of the sky where astronomers fear to look. Filled with dark clouds of dust, it hides an unseen mass. A mass so large it is pulling the Milky Way and other galaxies toward it…

Okay, maybe that’s overdramatic, but it is true. The region is known as the Zone of Avoidance, and it happens to be in the general direction of the galactic center. Our view of the Universe isn’t as perfect as we’d like. The Sun is located within the galactic plane of the Milky Way, about 30,000 light-years from its center. So if we look to the north or south of the galactic plane, we get a pretty normal view of the cosmos. We can peer deep into the sky and see distant galaxies. But if we look toward the galactic center, we don’t have a clear view. Instead, we see a bunch of stars, gas, and dust. This is fine if you want to study stars, gas, and dust, but it means our view of the distant Universe is obscured in that direction. So if you want to make an unbiased view of the cosmos, you avoid that region, hence the term.

It’s also true that we’re being pulled in that direction. There happens to be a supercluster of galaxies that way, called the Great Attractor. We can map it out a bit by studying the relative motion of nearby galaxies, and we can observe X-rays from the supercluster, so we know it’s out there. But with all the gas and dust in the Zone of Avoidance, we can’t study it in the optical. One thing we know so far is that the Great Attractor actually consists of multiple clusters. The closest one is known as the Norma cluster, while a larger and more distant one is called the Vela supercluster. Still, there is much we don’t know about the region.

Fortunately, radio light can penetrate the dust of the Zone, so radio astronomers have tried to map the region. One downside is that radio telescopes often don’t have a large field of view, so it’s difficult to map the region. But a new work is making progress.

Observed galaxies within the Vela supercluster. Credit: Sambatriniaina H. A. Rajohnson, et al

The new study uses data from the MeerKAT array telescope in South Africa. MeerKAT is particularly sensitive to the radio emissions of neutral hydrogen, known as the HI or [21-centimeter line.](https://briankoberlein.com/blog/dark-line/) Since hydrogen is so abundant in the Universe, the distribution of hydrogen tells us the distribution of galaxies and clusters. The study mapped the region of the Zone in the direction of the Vela supercluster with enough resolution to distinguish individual pockets of neutral hydrogen, each surrounding a galaxy. In this way, the team was able to discover 719 galaxies within the Vela cluster. Less than a third of them had been known previously.

This was just the first detailed survey of the Vela supercluster by MeerKAT, and it shows the real power of this relatively new observatory. Future studies should give us an even better understanding of the zone astronomers so often avoid.

Reference: Sambatriniaina H. A. Rajohnson, et al. “Revealing hidden structures in the Zone of Avoidance — a blind MeerKAT HI Survey of the Vela Supercluster.” arXiv preprint arXiv:2411.07084 (2024).

The post Astronomers Defy the Zone of Avoidance to Find Hundreds of New Galaxies appeared first on Universe Today.